1. Technical Field
This invention relates generally to sights for hand-held weapons such as rifles, pistols and bows, and more particularly to such sights having a means for illuminating the sight in low-light and dark conditions.
2. History of Related Art
Many attempts have been made to provide a sight for guns and bows that is usable under daylight, low light, and night conditions. One attempt to provide an aiming sight usable under both day and night conditions is disclosed in U.S. Pat. No. 4,070,763 issued Jan. 31, 1978, to Stanley L. Carts, Jr. The Carts sight proposes the use of hollow light-absorbing fibers, or solid fibers having a transparent core, that are coated with a light-absorbing material, such as black glass, to keep light contained within the fiber. A small dot is observable only when the axis of the fiber is aligned within one milliradian of a line from the user""s eye to the radiation source. This requirement makes the sight difficult to use because of the time that may be required to xe2x80x9cfindxe2x80x9d the dot source and then align the weapon with the target without losing sight of the dot.
The use of light-gathering fluorescent fibers in a bow sight is disclosed in U.S. Pat. No. 5,442,861 issued Aug. 22, 1995, to Paul M. LoRocco, the inventor of the present invention. In his earlier invention, Mr. LoRocco discovered that the use of light-gathering fluorescent fibers dramatically increased the amount of light emitted from an end of the fiber, in both daylight and low light conditions. More recently, several arrangements for adapting light-gathering fluorescent fibers to a variety of weapon sights is disclosed in the present inventor""s co-pending U.S. patent application Ser. No. 08/506,722, filed Jul. 26, 1965. However, in both of the above-disclosed sight arrangements, if a natural light source is not available, such as under nighttime conditions, the end of the fiber is not noticeably visible.
Attempts to provide a weapon sight suitable for use under both daylight and nighttime conditions include reticles illuminated by an artificial light source, such as a small incandescent bulb, and light-emitting diodes. These arrangements require a source of electrical power such as batteries, rendering the device cumbersome and susceptible to failure if the electrical power source is interrupted. Other attempts to provide a weapon sight for use under day or night conditions includes the use of small phosphorescent dots or other shapes painted directly onto a portion of the sight. This latter arrangement often compromises the visibility of the sight under bright light conditions.
The present invention is directed to overcoming the problems set forth above. It is desirable to have a sight for weapons that is readily visible in the brightness of day or the darkness of night. It is also desirable to have such a sight that is easy to see and hold in a user""s line of vision while aligning the weapon with a target. Furthermore, it is desirable to have such a weapon sight that does not require a powered light source.
In accordance with one aspect of the present invention, a weapon sight includes an elongated optical fiber formed of a light-gathering, fluorescent plastic material. The elongated optical fiber has a first end in which light is emitted to provide an aiming indicia, a second end spaced from the first end, and an outer surface extending between the first and second ends. The weapon sight further includes a holder, attachable to the weapon, that is adapted to support the elongated optical fiber. The weapon sight further includes a phosphorescent, light-emitting member disposed at a position adjacent the elongated optical fiber.
Other features of the weapon sight embodying the present invention include the phosphorescent, light-emitting member being positioned elevationally below the elongated optical fiber when the holder is mounted on the weapon. Still other features include the light-emitting member being shaped to form an elongated strip having a surface aligned in parallel relationship with the elongated optical fiber. In other embodiments, the light-emitting member alternatively has a flat planar surface, or an angled or contoured surface adapted to focus light onto the outer cylindrical surface of the elongated optical fiber. The phosphorescent, light-emitting member may include a film formed of phosphorescent paint, a plastic material containing luminescent pigment, or a light-emitting radioactive material. Yet other features of the weapons sight embodying the present invention include the light-emitting member additionally or solely being disposed adjacent a transverse end wall of the elongated fiber at the second end of the fiber. Also, the elongated strip embodiment of the light-emitting member may be in the form of a replaceable insert. Still other embodiments of the weapon sight include the light-emitting member having a body shaped to define a screw having an outer surface defining screw threads adapted to mate with screw threads formed in a portion of the holder, and an end face having a light-emitting material deposited thereon. In this arrangement, the screw-shaped body of the elongated light-emitting member is disposed in coaxial alignment with the elongated optical fiber.
In accordance with another aspect of the present invention, a weapons sight includes an elongated optical fiber formed of a light-gathering fluorescent plastic material and a holder attachable to a weapon and adapted to support the elongated optical fiber. The weapons sight further includes an elongated light-reflecting member disposed at a position adjacent the elongated optical fiber.
Other features of the weapon sight embodying the present invention include the light-reflecting member comprising a film formed of light-reflective paint or a solid insert having a light-reflective surface. The light-reflective surface may either be a flat planar surface aligned in parallel relationship with the elongated optical fiber or a contoured surface adapted to focus reflected light onto an outer cylindrical surface of the elongated optical fiber.